1. Field of the Invention
The present invention relates to an IC card connector capable of accommodating an IC card (i.e., card incorporating an integrated circuit or the like) which is provided with at least one embossed data field or row. More particularly, the present invention is concerned with an IC card connector which is imparted with a function for preventing erroneous insertion of an IC card and which can be applied advantageously and profitably to an automobile-onboard terminal for an automated road toll charging/collecting system and the like.
2. Description of Related Art
In recent years, IC cards incorporating an IC memory in which personal data can be readably written are widely employed for personal identification, automated monetary or other transactions and applications. The fields in which these IC cards find utilization is increasing. Such being the circumstances, the number of IC cards is increasing.
In general, the IC card of this type is adapted to be inserted into an IC card connector designed for reading data from the IC card. In the state of the art, various approaches have been made for enabling the IC card to be inserted into the IC card connector correctly with enhanced reliability. By way of example, there may be mentioned an arrow printed on the IC card for indicating the inserting direction and an erroneous insertion preventing mechanism provided for the IC card connector in order to prevent erroneous insertion of the IC card in the IC card connector.
Furthermore, there are used a variety of cards provided with embossed data row or rows having character information, such as cash cards and credit cards. Such being the case, an IC card connector is in demand with a structure that is capable of accommodating an IC card having embossed data row(s) as well. IC card having embosse data row(s) as well.
For having better understanding of the present invention, background techniques thereof will be described by reference to FIGS. 5 and 6 which show in perspective views, respectively, a conventional IC card and a conventional IC card connector known heretofore which is provided with an erroneous insertion preventing mechanism implemented by resorting to a unique geometrical configuration, as disclosed, for example, in Japanese Unexamined Patent Application Publication No. 266998/1990 (JP-A-2-266998).
Referring to FIG. 5, an IC card 1 includes a contact array 11 mounted on a top surface thereof, being exposed so as to serve as electrodes for an IC memory. One lateral edge portion of the IC card 1 is bent substantially in an L-like shape as viewed in cross section, whereby a bent edge 2 is formed.
On the other hand, an IC card connector 3 adapted for reading out information carried by the IC card 1 includes a slot 4 having a width H and a clearance W which allow the IC card 1 to be inserted therein, wherein a bent slot portion 4a is formed at one lateral end of the slot 4, as can be seen in FIG. 6.
Provided internally of the IC card connector 3 is a contact pin array (not shown) which is resiliently pressed onto the contact array 11 of the IC card 1. When the IC card 1 is inserted into the IC card connector to a proper position, the contact pin array is brought into electric contact with the contact array 11 to thereby enable the operation for reading out information or data from the IC card 1.
The bent slot portion 4a of the slot 4 is formed in a shape which coincides with that of the bent edge 2 of the IC card. By virtue of this arrangement, only the IC card 1 inserted into the IC card connector 3 in the correct orientation can be received and accommodated within the IC card connector 3 by way of the slot 4 and the bent slot portion 4a.
By using the IC card 1 formed with the bent edge 2 in combination with the IC card connector 3 provided with the slot 4 having the bent slot portion 4a of the shape coinciding with that of the bent edge 2 of the IC card, as described above, it is certainly possible to prevent the erroneous insertion of the IC card 1.
However, the IC card 1 is required to be formed in a unique geometrical configuration, as can be seen in FIG. 5. In addition, the erroneous insertion preventing function of the IC card connector 3 is effective only for the IC card 1 with the unique geometrical configuration, as can be seen in FIG. 6.
FIG. 7 is a side elevational view showing schematically another conventional IC card connector known heretofore in the state where an IC card 1A having an embossed data row 5 is inserted erroneously. Referring to FIG. 7, the IC card connector 3A is provided with a slot 4 which presents a relatively small clearance WA of a constant size over the whole width so that the IC card connector 3A can handle the IC card provided with no embossed data row 5.
In the case of the IC card and the IC card connector shown in FIG. 7, user tries to insert forcibly the IC card 1A having the embossed data row 5 into the slot 4. As a result of this, the slot 4 is partially expanded by the embossed data row 5. Thus, distortion occurs in the IC card connector 3A as indicated by 3d.
In general, the clearance defined by the slot of the IC card connector is formed to be constant over the whole width of the slot. Accordingly, the IC card connector can not deal with the IC card 1A having the embossed data row 5. When the clearance WA is dimensioned in a small size for the purpose of implementing the IC card connector in a small size or miniaturized structure, as illustrated in FIG. 7, interference between the embossed data row 5 and the slot 4 will occur to make it difficult to insert the IC card 1A due to an excessively large friction.
Furthermore, when the distortion 3d takes place due to the interference with the embossed data row 5, as shown in FIG. 7, contact pressure between the contact pin array provided internally of the IC card connector 3A and the contact array of the IC card 1A becomes insufficient, incurring undesirably a contact failure.
On the other hand, in case the clearance of the slot is formed in a large size with a view to evading interference with the embossed data row 5, the IC card connector will necessarily be realized in a large size. In that case, sufficient thickness can not be assured for a member which forms or defines the slot. This in turn means that sufficient strength can not be ensured for the IC card connector receiving portion of the IC card connector which is thus likely to undergo warp and distortion.
Additionally, when the clearance of the slot of the IC card connector is selected large, the IC card 1A having the embossed data row 5 inserted upside down may unwantedly be received by the IC card connector without any appreciable interference. In other words, erroneous insertion of the IC card 1A may possibly take place.
As will be appreciated from the foregoing, the conventional IC card connector 3 having the slot 4 of the unique geometrical configuration only for the purpose of preventing the erroneous insertion (see FIG. 6) is necessarily limited to handling only of the IC card 1 having a similar unique geometrical configuration (shown in FIG. 5), giving rise to the problem that this IC card connector can not handle other types of cards.
On the other hand, when the clearance WA of the slot 4 of the IC card connector 3A is designed in a small size with a view to realizing the IC card connector 3A in a small size, as shown in FIG. 7, proper insertion of the IC card 1A having the embossed data row 5 is rendered difficult or impossible, incurring occurrence of the distortion 3d due to interference between the embossed data row 5 and the slot 4, as a result of which various inconveniences are involved, to another problem.
On the other hand, when the clearance of the slot of the IC card connector is enlarged with a view to avoiding interference with the embossed data row 5, it will become difficult or impossible to ensure a high strength for the structure constituting the slot. Besides, erroneous insertion of the IC card can not be prevented at all, to another disadvantage.